Noise pollution in intensive care units and emergency wards.

Introduction: The improvement of technology has increased noise levels in hospital Wards to higher than international standard levels (35-45 dB). Higher noise levels than the maximum level result in patient’s instability and dissatisfaction. Moreover, it will have serious negative effects on the staff’s health and the quality of their services. The purpose of this survey is to analyze the level of noise in intensive care units and emergency wards of the Imam Reza Teaching Hospital, Mashhad. Procedure: This research was carried out in November 2009 during morning shifts between 7:30 to 12:00. Noise levels were measured 10 times at 30-minute intervals in the nursing stations of 10 wards of the emergency, the intensive care units, and the Nephrology and Kidney Transplant Departments of Imam Reza University Hospital, Mashhad. The noise level in the nursing stations was tested for both the maximum level (Lmax) and the equalizing level (Leq). The research was based on the comparison of equalizing levels (Leq) because maximum levels were unstable. Results: In our survey the average level (Leq) in all wards was much higher than the standard level. The maximum level (Lmax) in most wards was 85-86 dB and just in one measurement in the Internal ICU reached 94 dB. The average level of Leq in all wards was 60.2 dB. In emergency units, it was 62.2 dB, but it was not time related. The highest average level (Leq) was measured at 11:30 AM and the peak was measured in the Nephrology nursing station. Conclusion: The average levels of noise in intensive care units and also emergency wards were more than the standard levels and as it is known these wards have vital roles in treatment procedures, so more attention is needed in this area.


Introduction
Noise is an accidental sound wave without any rhythm or harmony which can interfere with hearing. Noise pollution is defined as the level of environmental noise that is annoying. Noises higher than 85 dB cause hearing problems. Even though noises with lower intensities do not lead to serious hearing problems, they can cause several harmful effects such as negative physiological consequences, deficient speaking awareness and recognition, and limited personal privacy. While the effects of noise in hospitals are not exactly known, there is no doubt that noise has different effects on patients' and staffs' well-being.
Continued presence of noise in the environment will cause an increase in the risk of high blood pressure and ischemic heart diseases in patients. It slows down healing and may contribute to patients' aggressive behaviors as well (1)(2)(3)(4).
Moor and his colleagues added that noise is the most important factor in provoking pain during the bedridden and postsurgical periods (3 However, in other wards, it was not higher than 88 dB.
In most wards, 9:30 to 11:00 during the morning was the peak of noise level. The Nephrology Unit and the Triple Emergency Units were found to be the noisiest places in different shift hours ( Table 1).
The equalized noise levels in the Internal, Surgical and Cardiovascular Emergency Units were 62.9 dB, 62.4 dB and 62.2 dB, respectively. In this research, the noise level was higher than 60 dB in the Pediatric and Internal ICUs while it was only 59 dB in the Open Heart ICU, which was considered the quietest unit. The noisiest was the Internal ICU (61.3 dB).
The time of peak level in ICUs was 9:30 a.m. In the NICU, the equalized level was 60.8 dB. In CCU wards, this level was 54-56 dB, and the time of peak was 11:30 A.M (Fig 1).   Telephone ringtones, and medical beeping instruments and alarms are tiring and bring about irritation to patients and probably lead to doctors' mistakes and may even increase the death rate (11).
Some studies have shown that normal sleeping problems of the staff is due to ICU noises (4). In a research in Greece, the noise level in ICUs was reported to be 27 dB more than standard limits (67 dB) (12).
In another research in ICU units, the time of noise pollution of each instrument was separately examined, which showed that the main cause of noise pollution of ICU environments was television (23%). Cardiac monitor alarms were in the second place. Based on this research, which was done by Douglas, et al, television and people speaking in the environment account for 49 percent of noise (13).
Although the Open Heart Surgery Ward was considered the quietest place, the noise level was 59 dBA, which is also far beyond the standard levels.
The noisiest ICU was the Internal ICU. The maximum of Leq in this ICU is around 9:30 A.M. In the NICU, the average noise level was 60.8 dB, which was mainly caused by from personnel's talking and also patients' relatives speaking with each other. We saw an increase when babies cried and also when heart monitors alarms were set off.
The noise level in the feeding room of babies should not exceed 35-55 dBA.
In our study, there was a significant difference between the current situations in the NICU and the standard conditions, and this pollution causes stress in babies, which results in physiological changes such as apnea, bradycardia, a decrease in the temporary pressure of oxygen and an increase in the required calories, which results in difficulty in babies gaining weight and also results in the lowering of neurological skills of the baby. On the Contrary, Pilibin and Gary claimed that change in Staffs behavior has no significant effect on the control of sound pollution in hospital words. However, more important effect is associated to physical changes that must be done in these wards (16). According, in another study performed in an oncology department, researchers succeeded in reducing the noise level up to 50 dB by installing acoustic fiberglass sheets on walls and ceilings (17).
In addition, in another study some interventions were performed to reduce the noise level of nightshifts in surgical ICU such as: reducing the sound of alarms, low-voiced conversation, no use of telephone ring, radio and television (18).

Conclusion
The sound level in all Imam Reza Hospital Wards evaluated in is study, was beyond the standard limit. Nephrology department and triple emergency ward were considered the noisiest places in different hours of the shift. The maximum point of the sound level was between q: 30 to N: 30 This research must be one the other department and in other shift times and the staff of treatment team must be taught how to reduce the controllable noises.
Equipments and standard procedures must be used to reduce the noise level in different hospital wards as well.